1. Field of the Invention
The invention relates to a multiple-speed, fully synchronized manual transmission for motor vehicles.
2. Description of the Prior Art
European Patent Document EP-B-O 128 319 describes a multiple-speed transmission for motor vehicles. The driving shaft of the transmission carries both fixed and loose gearwheels that mesh with corresponding loose and fixed gearwheels on the driven shaft. Between each pair of adjacent loose gearwheels there is located a synchronizing unit of conventional design to enable the adjacent loose gearwheels to be connected to their corresponding shafts.
It is a disadvantage of this gearbox that the synchronizing unit for the first and second gear is located on the driven shaft because the force required to produce synchronized gear shifts between first and second gear is greater, and the time required to make such gear shifts is longer, by about the transmission ratio of the first or second gear than would be the case if the synchronizing unit were located on the driving shaft.
This item has been universally accepted as a disadvantage by those skilled in the art because the usual reduction ratios of the individual gears in a multiple-speed gearbox and the resulting diameters of the various sets of gearwheels do not allow for a synchronizer to be located on the driving shaft if the shafts and gearwheels are of a size such that they have adequate strength.